ADTRAN Express L128T S User Manual page 132

Chapter 4. Troubleshooting
1. Cycle power on the Express L128T S/T, leaving it off for a
minimum of two seconds; then turn the power on for one minute
to ensure the PWR LED still does not stay on.
2. Disconnect the Express L128T S/T. From a functioning voice
phone, call the local directory number(s) provided with your line.
Calling a good ISDN line with nothing connected usually results
in a ring or fast busy tone. If someone answers, or you get a not-
in-service intercept, there is probably something wrong with the
translation of the line. The phone service provider should be able
to help.
3. If the PWR LED still flashes, there is a physical problem with the
phone line (more than likely, a problem with the Layer 1 setup).
The problem is in one or more of the places listed below:
• The Express L128T S/T software setup
• The Express L128T S/T hardware
• The wiring on your premises
• The telephone service provider's wiring
• The telephone service provider's hardware
• The telephone service provider's software setup
To isolate the problem, perform the following procedure:
A. Ensure the line is plugged into the Express L128T S/T con-
nector marked ISDN on the back of the Express L128T S/T.
B. Make sure the Express L128T S/T is configured for Dial line
service.
C. If possible, try another piece of functioning ISDN equipment
with an S/T interface on the line.
D. Talk to your service provider and ensure you have an ISDN
Basic Rate S/T Interface.
E. Ensure that your phone line is connected to the actual tele-
phone line (S/T interface) provided by your telephone com-
pany. Make sure your line is not connected through another
piece of equipment in a wiring closet.
F. Make sure nothing else is bridged across the line pair.
G. With a minimum of extra wiring, try connecting to the line
pair at the point where the service provider's wiring ends.
4-2 Express L128T S/T User Manual 61202070L3-20